Patient preparation is summarised in Table 3.
Scheduling of MRI examination according to the menstrual cycle is not necessary. This agrees with the majority of authors in the literature .
It is recommended to obtain specific clinical information at the time of the scan: date of last menstruation, clinical symptoms and previous gynaecological surgery.
Fasting and spasmolytic agents
In line with previous ESUR guidelines [9,10,11], it is recommended to fast before the examination (3–6 h) and to administer spasmolytic agents (20 mg of butylscopolamine or 1 mg glucagon (IV/IM), unless contraindicated) to reduce bowel motion artefact and obtain high-quality MR imaging.
It is recommended to achieve a moderately filled bladder, in line with previous ESUR guidelines [9,10,11].
Vaginal opacification with gel can be useful in the assessment of vaginal anomalies, which are often overlooked in the absence of appropriate vaginal distension (Fig. 2a) [12, 13].
The use of intracavitary gel facilitates identification and characterisation of a vaginal septum, both transverse and longitudinal, on T2W sequences (Fig. 3) . In addition, it helps to evaluate partial vaginal agenesis or segmental vaginal atresia before the surgical treatment .
The visualisation of vaginal/vulvar cysts is simplified and that of cervix/double cervix may also be improved (Fig. 2b) .
Vaginal filling is inexpensive and well tolerated . Self-application of gel by the patient, when feasible, is a good strategy to overcome religious and personal issues, regarding vaginal manipulation. Additionally, it has the advantage not to overload the radiology staff when availability of time is limited.
A consensus was not reached among the respondents regarding vaginal gel use.
In the study of FGTCA, the MRI protocol is based on the use of multiplanar 2D T2W high-resolution TSE/FSE sequences. T2W images require a slice thickness ≤ 4 mm with high matrix (512 × 512) and a small FOV to obtain a higher spatial resolution (Fig. 4a, b). Fat suppression is not recommended, due to the inherent contrast between the signal intensity of the uterus and the surrounding fat.
Multiplanar imaging is mandatory, and dedicated planes should be obtained along the long and short axis of the uterine body (yielding true coronal and true axial images of the uterus) in order to evaluate the external fundal contour and the cavity shape. For the purpose of uterine malformation classification, imaging the uterus in its true coronal plane is the most critical (Fig. 4) .
An oblique sequence obtained perpendicular to the cervical canal results in a short-axis view and allows accurate assessment of the cervix, i.e. the diagnosis of duplication or septation .
T1W FS sequences are required to detect blood products, in particular to evaluate the presence of haematometra, haematocolpos or endometriosis .
A coronal T2W sequence with a large FOV (such as SSFSE) should be acquired to evaluate the presence, position and morphology of the kidneys . Additionally, this sequence can detect ectopic ovaries, which sometimes lie above the pelvic brim, outside the standard field for pelvic assessment, and may be reported as absent (Fig. 5) .
Gadolinium-based contrast agent is generally selectively used to assess incidentally detected coexisting conditions . Delayed contrast-enhanced imaging may be useful if anomalous ureteral insertion is suspected .
In cases where a complex renal malformation is suspected, it might be useful to complete the examination performing MR-urography sequences.
Newer 3D T2W sequences seem to provide superior image quality and better 3D reconstructions compared with the classic 2D T2W sequences  with significant reduction in total scan time, compared with multiple 2D acquisitions . The precise planning of the conventional scanning planes is not required  as images can be reformatted in any plane, including curved MPR  and double oblique through the uterus . These 3D T2W sequences have different trade names: CUBE (GE), VISTA (Philips), SPACE (Siemens), among others .
Several MRI protocols for assessment of FGTCA are described in the literature. An abbreviated MRI protocol consisting of 3D T2W and non-enhanced axial T1W sequences for the pelvis and coronal SSFSE T2W sequences for the abdomen was recently proposed. This short protocol would provide useful information with regard to the uterine structure, the presence of blood products in the uterine cavity and the presence of renal anomalies .
The proposed ESUR-MRI protocol intends a dedicated evaluation of FGTCA (Table 4). Consensus was reached among the respondents.
Value of MRI in the evaluation of FGTCA, associated anomalies and complications
Uterus, cervix and vagina
MRI provides detailed information on the uterovaginal anatomy, particularly in the study of the external profile of the uterine fundus and the cavity shape, and it also allows tissue characterisation of the possible septa, thus providing a complete classification of the specific anomaly [22, 25]. Currently, MRI presents the highest diagnostic accuracy in the characterisation of uterine anomalies (nearly 100%), owing to an excellent soft tissue resolution and multiplanar capability [26,27,28].
MRI is more accurate than US in the detection of rudimentary horns and can discriminate a non-functional rudimentary horn from a functional non-communicating rudimentary horn, thanks to its ability to evaluate the zonal anatomy and signal intensity involving the endometrial cavity and the possible presence of haematometra [22, 29].
Kidney and ureter
Uterine anomalies are often associated with urinary tract malformations, as the embryological development of the urinary system is closely associated with that of the genital tract (Fig. 6) . Retrospective studies have demonstrated associated urinary tract anomalies in 17–42% of patients, with unilateral renal agenesis being the most common. Additional renal anomalies include multicystic dysplastic kidney, pelvic kidney, duplex kidney, horseshoe kidney and renal malrotation .
Patients with unilateral renal agenesis may have lower ureteric remnants inserting ectopically into the vagina, cervix and perineum, and distended with blood. Ectopic ureters have also been reported, with an apparently higher incidence compared with the general population . Accurate knowledge of the ureteric course, presence of ectopic ureter or ureteric remnant, may be important preoperative information .
Ovarian maldescent is defined as lack of normal descent of the ovary during the embryonic development. Ovaries may be found in an ectopic position along the migration pathway from the lumbar region to the ovarian fossa .
The incidence of ovarian maldescent is increased in patients with MDA (17%) compared with women with normal uterine morphology (3%) .
MRI is considered the best imaging technique in the evaluation of abnormally located ovaries [33, 34]. The limited FOV of transvaginal US can preclude their identification .
Fusion of vertebral bodies, hemivertebra, and malformation of the coccyx and sacral bone, scoliosis, have been reported in Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome [35, 36]. These anomalies can be evaluated within the imaged FOV of MRI examination.
Endometriosis and pelvic adhesions
Endometriosis and pelvic adhesions are potential long-term complications of obstructive anomalies, due to retrograde menstrual flow from the obstructed side. MRI can detect these complications [4, 37, 38].
Several classification systems exist for FGTCA; none of which is currently universally accepted, since all of them present some shortcomings.
In the medical literature, the ASRM classification is most widely used. In our group, the survey showed a slight preference for the ASRM classification over ESHRE/ESGE classification, probably reflecting that the ASRM classification was introduced earlier.
ASRM classification  distinguishes 7 different classes considering the Müllerian development and the relationship of the malformations to fertility [1, 4]. It is based mainly on uterine malformations while malformations of the vagina, adnexa or other associated malformations of non-Müllerian origin are not taken into account . Furthermore, more complex type of malformations or obstructive anomalies as a result of cervical and/or vaginal aplasia/dysplasia in the presence of a functional uterus is not considered .
The vagina cervix uterus adnexa and associated malformation (VCUAM) classification  and the Embryological-Clinical classification proposed by Acien and Acien  tried to overcome these limitations, but failed to gain widespread acceptance, probably due to its complexity.
In 2013, the ESHRE/ESGE classification was proposed, based on anatomical considerations (Supplementary Material Fig. 1). Congenital anomalies are classified into 6 main classes, expressing uterine anatomical deviations deriving from the same embryological origin. Cervical and vaginal anomalies are classified in independent supplementary sub-classes. A non-Müllerian duct anomaly, imperforate hymen, is included in sub-class V3, along with transverse vaginal septum .
While this most recent classification system has overcome some problems associated with previous systems , it was shown in a comparison of the ESHRE-ESGE classification with the ASRM classification using 3D US  that the application of the ESHRE-ESGE criteria resulted in a relative overdiagnosis of septate uteri and insufficient inter- and intra-rater reliability , which potentially might lead to unnecessary surgical overtreatment.
MR reporting of female genital tract congenital anomalies
The imaging approach can start with assessment of the uterus, cervix and vagina and ovarian location, followed by the evaluation of the kidneys and assessment of complications. Finally, a FGTCA classification system, ideally the same system used by the gynaecologist/surgeon at that institution, should be applied enabling efficient interdisciplinary communication.
A reporting checklist which highlights commonly overlooked imaging features is provided (Table 5).